This invention relates to an intravenous infusion assembly and more particularly to an infusion assembly for intravenous administration of fluids into small veins at areas of the body difficult to reach, such as scalp veins of an infant. However, an infusion assembly of this invention may advantageously be used for other purposes, as will be apparent to those familiar with the art.
Intravenous infusion assemblies in common use today employ so-called "winged" needles that include flexible plastic wings rigidly connected to small, metal needles and so designed that one may grip the wings, squeezing them between the thumb and forefinger, to assist in accurately positioning the needle and pushing it into the desired vein. U.S. Pat. No. 3,064,648, granted to Bujan on Nov. 20, 1962, illustrates a needle assembly of this type.
Those who use such needle assemblies have found them to be convenient and relatively easy to apply. However, since the metal needle is sharp pointed and rigid, relatively small movements of the needle after application and while in place in a vein may rupture the vein and permit the infusion fluid to infiltrate adjacent tissue. Because rupture of the vein is a likely occurrence, winged needle assemblies are more typically used only for short periods of time.
Needle and catheter sets of the type wherein the needle is inside a flexible catheter, such as shown in U.S. Pat. No. 3,094,122, issued Jan. 18, 1963, to Gauthier et al, possess substantial advantages, especially for use when infusion is to take place over an extended period of time. Their greatest advantage, of course, is that the flexible catheter is supported by the needle only during insertion into a vein and is all that remains in the vein. Unlike a needle, such a catheter is not rigid, does not have a sharp point and is not as likely to rupture the vein as a result of minor relative movements between the infusion assembly and the vein. However, such catheter and needle sets are not as convenient to administer in difficult locations because they are designed to be gripped from the rear, and thus one cannot control the position of the point of the needle with the ease and accuracy of the aforementioned devices having wings on needles.
A slidably mounted wing assembly on an over-the-needle catheter is described in U.S. Pat. No. 3,589,361, issued to Loper et al on June 29, 1971. However, it appears that the Loper device would be expensive to manufacture and cumbersome to use. So far as known, the device has not been generally accepted.